.container{
  display:flex;
  .nav-left{
    height: calc(100vh);
    color:#fff;
    background:#001529;
  }
  .main{
    flex:1;
    background:#f1f3f5;
    height:calc(100vh);
    overflow:auto;
  }
  .content{
    position:relative;
    padding: 20px;
  }
}